Aidan O'Brien, fresh from saddling the second, third, fourth and fifth in the Investec Derby, is responsible for the first four in the betting with sponsors Ladbrokes for the St Leger at Doncaster on September 12.
Heading the Ballydoyle challenge is Epsom runner-up Fame And Glory at 4-1, while the third across the line, Masterofthehorse, is next best at 6-1.
Ladbrokes spokesman David Williams said: "Once again it seems that Ballydoyle already hold the key to the race and they dominate the big-race betting.
"Fame And Glory's second at Epsom sets the standard for the time being."
O'Brien has landed the world's oldest Classic three times with Milan in 2001, Brian Boru in 2003 and Scorpion two years later.
Ladbrokes St Leger, sponsors bet: 4-1 Fame And Glory, 6-1 Masterofthehorse, 10-1 Golden Sword, 12-1 Age Of Aquarius, Harbinger, 14-1 Mourayan, Dhushan, 20-1 Alwaary, 25-1 bar.